The Southern Illinois University School of Medicine requests support to purchase a new flow cytometer for our core lab. The requested BD FACSAria II will replace a FACSVantage that was purchased with a Shared Instrumentation Grant in 1993 and remains in use today as our only cell sorter, documenting an incredible return-on-investment for NCRR. However, this unit is quite outdated and no longer meets the research needs of our faculty. Furthermore, after 2009 the Vantage will no longer be supported by the vendor. The FACSAria II will support a core of 7 NIH-funded faculty members with diverse research interests, as indicated by their varied sources of NIH funding (NCI, NHLBI, and NIAID). FACSAria II technology will effectively increase the quality of their data collection, their available research options, and their overall productivity. The ability to obtain high-quality populations of sorted cells will contribute to more rapid advances in our understanding of the causes and course of cancer, infectious diseases, cell development, and other aspects of cellular and biomolecular processes. Because the FACSAria II allows rapid, reliable cell sorting, it reduces the cell loss and variability inherent in older systems. By increasing the temporal and spatial resolution of the sorting, the technology allows collection of specific but rare cell types from a heterogeneous population, thereby supporting precise and accurate characterization of therapeutic effects and normal versus pathological processes. These benefits will allow our NIH- funded and other investigators to advance their respective research areas in ways not otherwise possible with the tools currently available to them at SIUSM.